1. Field of the Invention
This invention relates to restraints that are used to provide protection for occupants of vehicles, and more particularly, to an inflatable safety cushion apparatus that is attachable to passive belt-type restraints.
2. Description of the Prior Art
Various forms of restraints have been proposed in the prior art for the protection of vehicle occupants. Specifically, there have been provided passive and inflatable seat belt systems, and static and inflatable air bag systems. Inflatable belt and inflatable air bag systems are designed to provide a greater degree of protection, than the passive seat belt and static air bag systems are capable of, for the vehicle occupants.
The inflatable restraint systems of the prior art are complex and expensive, and are characterized by their longer than desirable "reaction time," that is the length of time required for inflation and effective constraining action on the user upon a crash impact. Additionally, the prior art inflatable restraint systems are best suited for installation at the time of manufacture of the vehicle. Among the reasons for this is that the inflatable belt systems require, in addition to the use of a special inflatable belt, the mounting in the vehicle, on or under the floor thereof, of a pressurized gas supply that is connected to the inflatable belt by an elongated tube or pipe. The inflatable air bag systems involve mounting in the steering wheel hub and/or in the dashboard of the vehicle of a folded and compacted air bag that is inflatable to a relatively large volume, and a pressurized gas supply or gas generator.
With the inflatable belt-type restraint systems, an undesirable delay in the inflation of the inflatable belt is introduced because the gas must flow through the elongated tube from the pressurized gas supply. This extends the reaction time of the system beyond a value that is optimum for protection of the user in the most comfortable manner. The relatively larger volume of the air bag, and the relatively large distance between the folded and compacted bag and the user that must be traversed by the inflated bag, upon a crash impact, to constrain the user also cause the reaction time of the inflatable air bag restraint systems to be longer than desirable. As a consequence, for both the inflatable belt and the inflatable air bag restraint systems of the prior art, the longer than desirable reaction time upon a crash impact tends to allow some movement of the user to occur, thus exposing the user to an undesirable shock of sudden, hard constraint.
There thus exists a need in the art for an improved restraint for the protection of occupants of vehicles that functions, upon a crash impact, to soften the shock of sudden constraint against the user's body, and to maintain the restraint with an appropriate degree of tautness.
There further exists a need in the art for a simple and facile way to improve passive belt-type restraint systems that are already installed on vehicles to provide such greater degree of protection with a minimum of discomfort for the occupants of vehicles having such restraint systems.